Ten-Year Results of FAST: A Randomized Controlled Trial of 5-Fraction Whole-Breast Radiotherapy for Early Breast Cancer

Brunt, Adrian Murray; Haviland, Joanne S.; Sydenham, Mark; Agrawal, Rajiv K.; Algurafi, Hafiz; Alhasso, Abdulla; Barrett-Lee, Peter; Bliss, Peter; Bloomfield, David; Bowen, Joanna; Donovan, Ellen; Goodman, Andy; Harnett, Adrian; Hogg, Martin; Kumar, Sri; Passant, Helen; Quigley, Mary; Sherwin, Liz; Stewart, Alan; Syndikus, Isabel; Tremlett, Jean; Tsang, Yat; Venables, Karen; Wheatley, Duncan; Bliss, Judith M.; Yarnold, John R.

Abstract

PURPOSE: Previous studies of hypofractionated adjuvant whole-breast radiotherapy for early breast cancer established a 15- or 16-fraction (fr) regimen as standard. The FAST Trial (CRUKE/04/015) evaluated normal tissue effects (NTE) and disease outcomes after 5-fr regimens. Ten-year results are presented.

METHODS: Women = 50 years of age with low-risk invasive breast carcinoma (pT1-2 pN0) were randomly assigned to 50 Gy/25 fr (5 weeks) or 30 or 28.5 Gy in 5 once-weekly fr of 6.0 or 5.7 Gy. The primary end point was change in photographic breast appearance at 2 and 5 years; secondary end points were physician assessments of NTE and local tumor control. Odds ratios (ORs) from longitudinal analyses compared regimens.

RESULTS: A total of 915 women were recruited from 18 UK centers (2004-2007). Five-year photographs were available for 615/862 (71%) eligible patients. ORs for change in photographic breast appearance were 1.64 (95% CI, 1.08 to 2.49; P = .019) for 30 Gy and 1.10 (95% CI, 0.70 to 1.71; P = .686) for 28.5 Gy versus 50 Gy. a/ß estimate for photographic end point was 2.7 Gy (95% CI, 1.5 to 3.9 Gy), giving a 5-fr schedule of 28 Gy (95% CI, 26 to 30 Gy) estimated to be isoeffective with 50 Gy/25 fr. ORs for any moderate/marked physician-assessed breast NTE (shrinkage, induration, telangiectasia, edema) were 2.12 (95% CI, 1.55 to 2.89; P < .001) for 30 Gy and 1.22 (95% CI, 0.87 to 1.72; P = .248) for 28.5 Gy versus 50 Gy. With 9.9 years median follow-up, 11 ipsilateral breast cancer events (50 Gy: 3; 30 Gy: 4; 28.5 Gy: 4) and 96 deaths (50 Gy: 30; 30 Gy: 33; 28.5 Gy: 33) have occurred.

CONCLUSION: At 10 years, there was no significant difference in NTE rates after 28.5 Gy/5 fr compared with 50 Gy/25 fr, but NTE were higher after 30 Gy/5 fr. Results confirm the published 3-year findings that a once-weekly 5-fr schedule of whole-breast radiotherapy can be identified that appears to be radiobiologically comparable for NTE to a conventionally fractionated regimen.

Citation

Brunt, A. M., Haviland, J. S., Sydenham, M., Agrawal, R. K., Algurafi, H., Alhasso, A., …Yarnold, J. R. (2020). Ten-Year Results of FAST: A Randomized Controlled Trial of 5-Fraction Whole-Breast Radiotherapy for Early Breast Cancer

• Report Type: Other
• Acceptance Date: May 19, 2020
• Online Publication Date: Jul 14, 2020
• Publication Date: Oct 1, 2020
• Publicly Available Date: May 26, 2023
• Publisher: American Society of Clinical Oncology
• Pages: 3261-3272
• DOI: https://doi.org/10.1200/jco.19.02750
• Publisher URL: https://doi.org/10.1200/jco.19.02750
• Additional Information: Protocol paper